Monday, March 30, 2009

Leaf-Cutting Ants Help Develop New Drugs

In a spectacular case of symbiosis leaf-cutting ants have been cultivating fungus gardens that provide a safe home for the fungi and a food source for the ants for the last 50 million-years. It was only 10 years back that Cameron Currie, a microbial ecologist then at the University of Toronto in Ontario, Canada, discovered that leaf-cutting ants carry colonies of actinomycete bacteria on their bodies. This bacteria produce an antibiotic that protects the ants' fungal crops from associated parasitic fungi.

Currie was fascinated by his discovery and wanted to know the nitty gritty of the entire symbiosis.On 29 March, Currie, Jon Clardy at the Harvard Medical School in Boston and their colleagues reported that they had isolated and purified one of these antifungals. They named the new antifungal dentigerumycin. The story does not stop here. This newly discovered antifungal was found to slow down the growth of a drug-resistant strain of the fungus Candida albicans, which causes yeast infections in people. An excited Currie has described the ants as walking pharmaceutical factories. Different ant species cultivate different fungal crops, which in turn is affected by different parasites. So researchers are hoping to find and develop new drugs.

Another spin off of the research is the discovery that fungi associated with ants are very efficient at breaking down cellulose. Unravelling the process might allow us to make more efficient biofuels. than those made from sugary foods, such as maize.